--- gui.c.orig	Tue Feb  7 19:16:39 2006
+++ gui.c	Mon Aug  4 12:42:28 2008
@@ -69,7 +69,8 @@ static int resize(unsigned char *INbuff, unsigned char
 		Cc = 0;
 	    if (lastCc == Cc) {
 		/* no Chroma interleave correct by moving the index */
-		rx -= 1;
+		if (rx != 0)
+			rx -= 1;
 		Cc = !Cc;
 	    }
 	    memcpy(output++, &input[ADDRESSE((int) rx, (int) y, Owidth)],
